The contractor will coordinate the collection and reporting of clinical and typing data pertaining to renal transplants within his region in a format acceptable to the project officer, and will forward these reports to a central statistical center. In addition, he will maintain facilities for verifying the accuracy of the collected data and the thoroughness of the reporting. Specifically, the contractor will provide for the following: Accuracy and completeness of the clinical data by maintenance of a close liaison with participating centers within his region; Quality control of histocompatibility typing procedures and the verification of typing results through use of standardized NIH trays and supplemental typing serum; Frozen storage of collected serum from kidney recipients and cells from donors in order to allow retrospective typing when indicated. This project involves data collection only, and the use of humans as subjects in its performance is prohibited.